Official tsunami warnings in the U.S. began in 1949 as a response to the 1946 tsunami generated in the Aleutian Islands that devastated Hilo, Hawaiʻi. In the aftermath of the devastating 1960 Chilean earthquake and tsunami, the nations of the Pacific decided to coordinate efforts to warn of ocean-crossing tsunamis. Under the auspices of the United Nations, the Intergovernmental Oceanographic Commission (IOC) established the Intergovernmental Coordination Group for the Pacific Tsunami Warning System (ICG/PTWS) in 1968 at the National Weather Service’s Pacific Tsunami Warning Center (PTWC) in Hawai’i. Since it was founded, the PTWC has taken on additional areas of responsibility including the Indian Ocean, South China Sea, Caribbean Sea, and Puerto Rico & U.S. Virgin Islands and is staffed 24 hours a day, every day. Much of this growth was due to increasing loss of life and property due to tsunamis, but also due to an innovative tsunami monitoring and warning system developed by NOAA scientists.
The DART® System
Researchers at NOAA’s Pacific Marine Environmental Laboratory (PMEL) in Seattle, Washington, developed the first DART® system in 1995, but it wasn’t until the Indian Ocean tsunami disaster in December 2004 that the system was implemented throughout the waters of the Pacific and Indian Oceans.
A Deep-ocean Assessment and Reporting of Tsunamis or DART® system consists of a seafloor bottom pressure recording (BPR) system capable of detecting tsunamis as small as 1 cm, and a moored surface buoy for real-time communications. An acoustic link is used to transmit data from the BPR on the seafloor to the surface buoy. The data are then relayed via a satellite link to ground stations, which translate the signals for immediate transmission to NOAA's Tsunami Warning Centers and to PMEL.
The DART® buoy system received a patent (US 7,289,907) in 2007 and was successfully licensed to Science Applications International Corporation (SAIC) for production and sales. The DART® system is widely deployed near regions with a history of tsunami generation, to ensure measurement of the waves as they propagate towards threatened U.S. coastal communities and to acquire data critical to real-time forecasts.